In multidimensional tests, the identification of latent traits measured by each item is crucial. In addition to item–trait relationship, differential item functioning (DIF) is routinely evaluated to ensure valid comparison among different groups. The two problems are investigated separately in the literature. This paper uses a unified framework for detecting item–trait relationship and DIF in multidimensional item response theory (MIRT) models. By incorporating DIF effects in MIRT models, these problems can be considered as variable selection for latent/observed variables and their interactions. A Bayesian adaptive Lasso procedure is developed for variable selection, in which item–trait relationship and DIF effects can be obtained simultaneously. Simulation studies show the performance of our method for parameter estimation, the recovery of item–trait relationship and the detection of DIF effects. An application is presented using data from the Eysenck Personality Questionnaire.

Characterised by the extensive use of obsidian, a blade-based tool inventory and microblade technology, the late Upper Palaeolithic lithic assemblages of the Changbaishan Mountains are associated with the increasingly cold climatic conditions of Marine Isotope Stage 2, yet most remain poorly dated. Here, the authors present new radiocarbon dates associated with evolving blade and microblade toolkits at Helong Dadong, north-east China. At 27 300–24 100 BP, the lower cultural layers contain some of the earliest microblade technology in north-east Asia and highlight the importance of the Changbaishan Mountains in understanding changing hunter-gatherer lifeways in this region during MIS 2.

The Chinese Loess Plateau (CLP), recognized as the world's largest loess plateau, has been a subject of ongoing debate regarding the continuity of its sedimentary loess sequence due to its intricate depositional environment. In this study, we conducted dating on a 9.8-m-long Malan loess core obtained from the Sanmen Gorge in the southern CLP using optically stimulated luminescence (OSL). The OSL dates indicate loess deposition between 52.4 and 11.3 ka, with no apparent hiatus on a millennial scale, and a sedimentation rate (SR) exhibiting six distinct episodes. Additionally, a comprehensive review of 613 OSL ages from 18 sections at 14 sites across the CLP was conducted. The results reveal loess deposition at most sites shows no apparent hiatus on a millennial scale over the past 60 ka, except for two specific locations. High SR episodes during Marine Isotope Stage (MIS) 3 across the CLP were attributed to heightened dust emissions from the source region and an enhanced dust deposition efficiency, while MIS 2 deposits were influenced by an intensified East Asian winter monsoon. Low SR episodes during MIS 1 at most sites were likely associated with reduced atmospheric transportation and pedogenesis. Spatially heterogeneous SR variations across the CLP might be influenced by local depositional environments.

Extreme heat events in the summer of 2022 were observed in Eurasia, North America and China. Glaciers are a unique indicator of climate change, and the European Alps experienced substantial glacier mass loss as a result of the conditions in 2022, which prompted a wide range of community concerns. However, relevant findings for glaciers in China have not been currently reported. Here, we document the response of Urumqi Glacier No. 1 in the eastern Tien Shan to the extreme heat observed in 2022 based on in situ measurements that span more than 60 years. In 2022, Urumqi Glacier No. 1 exhibited the second largest annual mass loss on record, and the summer mass balance was the most negative on record. The hottest summer on record and relatively lower solid precipitation ratio contributed to the exceptional mass losses at Urumqi Glacier No. 1 in 2022, demonstrating the significant influence of heatwaves on extreme glacier melt in China.

Childhood maltreatment is an established risk factor for psychopathology. However, it remains unclear how childhood traumatic events relate to mental health problems and how the brain is involved. This study examined the serial mediation effect of brain morphological alterations and emotion-/reward-related functions on linking the relationship from maltreatment to depression. We recruited 156 healthy adolescents and young adults and an additional sample of 31 adolescents with major depressive disorder for assessment of childhood maltreatment, depressive symptoms, cognitive reappraisal and anticipatory/consummatory pleasure. Structural MRI data were acquired to identify maltreatment-related cortical and subcortical morphological differences. The mediation models suggested that emotional maltreatment of abuse and neglect, was respectively associated with increased gray matter volume in the ventral striatum and greater thickness in the middle cingulate cortex. These structural alterations were further related to reduced anticipatory pleasure and disrupted cognitive reappraisal, which contributed to more severe depressive symptoms among healthy individuals. The above mediating effects were not replicated in our clinical group partly due to the small sample size. Preventative interventions can target emotional and reward systems to foster resilience and reduce the likelihood of future psychiatric disorders among individuals with a history of maltreatment.

The efficient separation of hexane isomers from the light naphtha fraction is a significant challenge in the petrochemical industry. 5A zeolite adsorbent is used commercially to sieve alkane isomers. In this study, 5A zeolites were synthesized using a low-cost natural clay mineral precursor, i.e. palygorskite (PAL), with the addition of crystallization directing agent (CDA). By varying the mass ratio of CDA/deionized water, 5A zeolites were obtained as CDA-5%, CDA-7.5%, and CDA-10%. All products were submicron particles with an average particle size of 400–800 nm. A sieving test of CDA-induced 5A zeolites was carried out on hexane adsorbates including n-hexane (nHEX), 2-methylpentane (2MP), and 3-methylpentane (3MP). According to vapor-phase batch adsorption experiments, a significant equilibrium amount (0.149 g/g) of nHEX and only 0.0321 g/g 2MP and 0.0416 g/g 3MP were adsorbed on the 5A zeolite product with CDA-5%. The dynamic adsorption performance of 5A zeolite (CDA-5%) was evaluated by breakthrough curves of binary mixtures of nHEX/2MP and nHEX/3MP. Palygorskite 5A (PAL 5A) zeolite achieved maximum dynamic adsorption capacities of nHEX (0.16 g/g in both cases) at 200°C and 1.2 MPa total pressure. This work provided an economic alternative for the synthesis of 5A zeolites using natural clay minerals instead of chemical raw materials.

The construction of organic-inorganic hybrid ferroelectric materials with larger, high-polarity guest molecules intercalated in kaolinite (K) faces difficulties in terms of synthesis and uncertainty of structure-property relationships. The purpose of the present study was to optimize the synthesis method and to determine the mechanism of ferroelectric behavior of kaolinite intercalated with p-aminobenzamide (PABA), with an eye to improving the design of intercalation methods and better utilization of clay-based ferroelectric materials. The K-PABA intercalation compound (chemical formula Al2Si2O5(OH)4∙(PABA)0.7) was synthesized in an autoclave and then characterized using X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The experimental results showed that PABA expanded the kaolinite interlayer from 7.2 Å to 14.5 Å, and the orientation of the PABA molecule was ~70° from the plane of the kaolinite layers. The amino group of the PABA molecule was close to the Si sheet. The presence of intermolecular hydrogen bonds between kaolinite and PABA and among PABA molecules caused macro polarization of K-PABA and dipole inversion under the external electric field, resulting in K-PABA ferroelectricity. Simulation calculations using the Cambridge Sequential Total Energy Package (CASTEP) and the ferroelectricity test revealed the optimized intercalation model and possible ferroelectric mechanism.

Limonite is mainly derived from weathering of Fe sulfide, iron-bearing carbonate, or silicate minerals. The weathering of Fe sulfide or carbonate minerals to yield limonite from the Tongling mineralization cluster has been studied extensively. Knowledge of the mineralogical and geochemical characteristics of the limonite from weathering of Fe-bearing silicate minerals is still incomplete, however. To address this, black limonite containing ilvaite (a silicate mineral) found in Yeshan iron deposit, Tongling, China, was studied using mineralogical and chemical analysis. The mineralogical characteristics indicated that Mn goethite was present as nano-granular (<15 nm) or acicular (50–100 nm long, ~10 nm wide, i.e. high length/width ratio) crystals with low crystallinity. Groutite, ramsdellite, and pyrolusite were identified in the limonite as ~5 nm nanoparticles, and coated on the goethite surface. Amorphous Fe-Mn phases and silica were highly developed in the limonite studied. Ilvaite crystals showed idiomorphic granular morphology and were replaced by Fe-Mn oxides/hydroxides; pyrite was also present as inclusions within the ilvaite and the ilvaite structural formula calculated was Ca1.04(Fe1.57Mn0.31Mg0.04)(Fe1.09Al0.01)[Si1.95O]O(OH). According to the relatively high CuO and ZnO values and the low Al2O3 value in the black limonite, the negative correlations between (Fe2O3+MnO) and (CuO+ZnO+BaO), (Fe2O3+MnO) and Al2O3, high Mn and Si contents, and the characteristics of the textural relationships and compositions between the black limonite and ilvaite, a semi-enclosed environment with acidic to weakly alkaline conditions was deduced; ilvaite was found to be responsible for the formation and enrichment of limonite.

Tumor theranostics (a portmanteau of therapeutics and diagnostics) is now achieved in various ways with complex nanoparticle systems. Layered double hydroxide (LDH) nanoparticles are effective at drug/gene delivery and as imaging agents in potential tumor theranostics. This mini-review paper summarizes recent progress in developing LDH nanoparticles as a pH-sensitive magnetic resonance imaging (MRI) contrast agent, as a positron emission tomography (PET) imaging agent, and as a co-delivery platform for two therapeutic agents for tumor diagnosis and therapy. These results have indicated clearly the potential application of LDH nanoparticles for simultaneous diagnosis and treatment of cancers.

Let G be a graph with no isolated vertex. A semitotal forcing set of G is a (zero) forcing set S such that every vertex in S is within distance 2 of another vertex of S. The semitotal forcing number $F_{t2}(G)$ is the minimum cardinality of a semitotal forcing set in G. In this paper, we prove that it is NP-complete to determine the semitotal forcing number of a graph. We also prove that if $G\neq K_n$ is a connected graph of order $n\geq 4$ with maximum degree $\Delta \geq 2$, then $F_{t2}(G)\leq (\Delta-1)n/\Delta$, with equality if and only if either $G=C_{4}$ or $G=P_{4}$ or $G=K_{\Delta ,\Delta }$.

Childhood maltreatment has been suggested to have an adverse impact on neurodevelopment, including microstructural brain abnormalities. Existing neuroimaging findings remain inconsistent and heterogeneous. We aim to explore the most prominent and robust cortical thickness (CTh) and gray matter volume (GMV) alterations associated with childhood maltreatment. A systematic search on relevant studies was conducted through September 2022. The whole-brain coordinate-based meta-analysis (CBMA) on CTh and GMV studies were conducted using the seed-based d mapping (SDM) software. Meta-regression analysis was subsequently applied to investigate potential associations between clinical variables and structural changes. A total of 45 studies were eligible for inclusion, including 11 datasets on CTh and 39 datasets on GMV, consisting of 2550 participants exposed to childhood maltreatment and 3739 unexposed comparison subjects. Individuals with childhood maltreatment exhibited overlapped deficits in the median cingulate/paracingulate gyri simultaneously revealed by both CTh and GM studies. Regional cortical thinning in the right anterior cingulate/paracingulate gyri and the left middle frontal gyrus, as well as GMV reductions in the left supplementary motor area (SMA) was also identified. No greater regions were found for either CTh or GMV. In addition, several neural morphology changes were associated with the average age of the maltreated individuals. The median cingulate/paracingulate gyri morphology might serve as the most robust neuroimaging feature of childhood maltreatment. The effects of early-life trauma on the human brain predominantly involved in cognitive functions, socio-affective functioning and stress regulation. This current meta-analysis enhanced the understanding of neuropathological changes induced by childhood maltreatment.

The relationship between immigration and welfare provision is at the heart of welfare politics research. While prior studies have examined how immigration affects welfare generosity, less is known about the consequences of exclusive welfare policies and immigration on social inequality. In this paper, by using TANF as the policy context, we offer a systematic examination of how immigration combined with state immigrant welfare policies affect inequality in welfare usage between citizens and immigrants. Using data across the fifty American states from 2001 to 2016, we find evidence that exclusive state immigrant TANF policies are a key source of decreased immigrant TANF caseload rate and enlarged citizen-immigrant TANF caseload gap. Moreover, states’ immigrant population density moderates the effect of state immigrant welfare eligibility policies on immigrant TANF caseload rate and citizen-immigrant TANF caseload gap. Our robustness checks by using alternative measures of the dependent variable and key independent variable verify these findings.